lib/php/src/transport/TFramedTransport.php

   1 <?php
   2
   3 /**
   4  * Copyright (c) 2006- Facebook
   5  * Distributed under the Thrift Software License
   6  *
   7  * See accompanying file LICENSE or visit the Thrift site at:
   8  * http://developers.facebook.com/thrift/
   9  *
  10  * @package thrift.transport
  11  * @author Mark Slee <mcslee@facebook.com>
  12  */
  13
  14 /**
  15  * Framed transport. Writes and reads data in chunks that are stamped with
  16  * their length.
  17  *
  18  * @package thrift.transport
  19  * @author Mark Slee <mcslee@facebook.com>
  20  */
  21 class TFramedTransport extends TTransport {
  22
  23   /**
  24    * Underlying transport object.
  25    *
  26    * @var TTransport
  27    */
  28   private $transport_;
  29
  30   /**
  31    * Buffer for read data.
  32    *
  33    * @var string
  34    */
  35   private $rBuf_;
  36
  37   /**
  38    * Buffer for queued output data
  39    *
  40    * @var string
  41    */
  42   private $wBuf_;
  43
  44   /**
  45    * Whether to frame reads
  46    *
  47    * @var bool
  48    */
  49   private $read_;
  50
  51   /**
  52    * Whether to frame writes
  53    *
  54    * @var bool
  55    */
  56   private $write_;
  57
  58   /**
  59    * Constructor.
  60    *
  61    * @param TTransport $transport Underlying transport
  62    */
  63   public function __construct($transport=null, $read=true, $write=true) {
  64     $this->transport_ = $transport;
  65     $this->read_ = $read;
  66     $this->write_ = $write;
  67   }
  68
  69   public function isOpen() {
  70     return $this->transport_->isOpen();
  71   }
  72
  73   public function open() {
  74     $this->transport_->open();
  75   }
  76
  77   public function close() {
  78     $this->transport_->close();
  79   }
  80
  81   /**
  82    * Reads from the buffer. When more data is required reads another entire
  83    * chunk and serves future reads out of that.
  84    *
  85    * @param int $len How much data
  86    */
  87   public function read($len) {
  88     if (!$this->read_) {
  89       return $this->transport_->read($len);
  90     }
  91
  92     if (strlen($this->rBuf_) === 0) {
  93       $this->readFrame();
  94     }
  95
  96     // Just return full buff
  97     if ($len >= strlen($this->rBuf_)) {
  98       $out = $this->rBuf_;
  99       $this->rBuf_ = null;
 100       return $out;
 101     }
 102
 103     // Return substr
 104     $out = substr($this->rBuf_, 0, $len);
 105     $this->rBuf_ = substr($this->rBuf_, $len);
 106     return $out;
 107   }
 108
 109   /**
 110    * Put previously read data back into the buffer
 111    *
 112    * @param string $data data to return
 113    */
 114   public function putBack($data) {
 115     if (strlen($this->rBuf_) === 0) {
 116       $this->rBuf_ = $data;
 117     } else {
 118       $this->rBuf_ = ($data . $this->rBuf_);
 119     }
 120   }
 121
 122   /**
 123    * Reads a chunk of data into the internal read buffer.
 124    */
 125   private function readFrame() {
 126     $buf = $this->transport_->readAll(4);
 127     $val = unpack('N', $buf);
 128     $sz = $val[1];
 129
 130     $this->rBuf_ = $this->transport_->readAll($sz);
 131   }
 132
 133   /**
 134    * Writes some data to the pending output buffer.
 135    *
 136    * @param string $buf The data
 137    * @param int    $len Limit of bytes to write
 138    */
 139   public function write($buf, $len=null) {
 140     if (!$this->write_) {
 141       return $this->transport_->write($buf, $len);
 142     }
 143
 144     if ($len !== null && $len < strlen($buf)) {
 145       $buf = substr($buf, 0, $len);
 146     }
 147     $this->wBuf_ .= $buf;
 148   }
 149
 150   /**
 151    * Writes the output buffer to the stream in the format of a 4-byte length
 152    * followed by the actual data.
 153    */
 154   public function flush() {
 155     if (!$this->write_) {
 156       return $this->transport_->flush();
 157     }
 158
 159     $out = pack('N', strlen($this->wBuf_));
 160     $out .= $this->wBuf_;
 161     $this->transport_->write($out);
 162     $this->transport_->flush();
 163     $this->wBuf_ = '';
 164   }
 165
 166 }